a. Field of Invention
The invention relates generally to a fuel cell compressor system, including a fuel cell compressor system that uses a gear set configured to drive an impeller at a speed greater than motor speed.
b. Description of Related Art
Fuel cells generally require clean, pressurized fluid to operate reliably. Centrifugal compressors designed for low flow, operate more efficiently at higher speeds. Accordingly, conventional centrifugal fuel cell compressors are typically directly driven by high-speed motors. However, the use of high-speed motors can involve some disadvantages. Among other things, sealed, greased bearings are commonly unable to adequately operate at such higher motor speeds. Also, while open oil bearings may operate at higher compressor speeds, their use requires inefficient, complex, oil lubrication systems to survive. Further, while air bearings can sometimes be used in higher-speed environments, and operate cleanly, such bearings are often expensive and impractical for mass production.
Consequently, there is a desire for a fuel cell compressor system that can operate with a low-speed motor, while retaining a sufficiently high compressor speed for efficient, reliable fuel cell operation. Further, there is a desire for a fuel cell compressor system that may be configured for operation with standard mass produced bearings that are otherwise typically not usable in connection with high-speed compressor operation.